/* ===== Variables ===== */
:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: #1a1f35;
    --bg-card-hover: #222845;
    --text-primary: #f0f2f5;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --accent-pink: #ec4899;
    --accent-green: #10b981;
    --accent-orange: #f59e0b;
    --accent-red: #ef4444;
    --accent-teal: #14b8a6;
    --gradient-primary: linear-gradient(135deg, #3b82f6, #8b5cf6, #ec4899);
    --gradient-hero: linear-gradient(135deg, #0a0e1a 0%, #1a1040 50%, #0a0e1a 100%);
    --border: rgba(255,255,255,0.08);
    --shadow: 0 4px 24px rgba(0,0,0,0.3);
    --radius: 16px;
    --radius-sm: 10px;
    --font-primary: 'Inter', -apple-system, sans-serif;
    --font-display: 'Space Grotesk', 'Inter', sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: var(--font-primary);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
select { font-family: inherit; }

/* ===== Navbar ===== */
.navbar {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(10, 14, 26, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}
.navbar.scrolled { background: rgba(10, 14, 26, 0.95); }
.nav-container {
    max-width: 1280px; margin: 0 auto;
    padding: 0 24px; height: 70px;
    display: flex; align-items: center; justify-content: space-between;
}
.nav-logo { display: flex; align-items: center; gap: 10px; font-size: 1.4rem; font-weight: 700; }
.logo-icon { font-size: 1.6rem; }
.logo-text { font-family: var(--font-display); }
.logo-accent { background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.nav-menu { display: flex; gap: 8px; list-style: none; }
.nav-link {
    padding: 8px 16px; border-radius: 8px; font-weight: 500; font-size: 0.95rem;
    color: var(--text-secondary); transition: var(--transition);
}
.nav-link:hover, .nav-link.active { color: var(--text-primary); background: rgba(255,255,255,0.06); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--text-primary); border-radius: 2px; transition: var(--transition); }

/* ===== Hero ===== */
.hero {
    min-height: 100vh; display: flex; align-items: center; justify-content: center;
    text-align: center; position: relative; overflow: hidden;
    background: var(--gradient-hero);
}
.hero-bg {
    position: absolute; inset: 0;
    background: radial-gradient(ellipse at 30% 20%, rgba(59,130,246,0.15) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 60%, rgba(139,92,246,0.1) 0%, transparent 50%),
                radial-gradient(ellipse at 50% 80%, rgba(236,72,153,0.08) 0%, transparent 50%);
}
.hero-bg::before {
    content: ''; position: absolute; inset: 0;
    background-image: radial-gradient(rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 40px 40px;
}
.hero-content { position: relative; z-index: 1; max-width: 800px; padding: 120px 24px 80px; }
.hero-badge {
    display: inline-block; padding: 8px 20px; border-radius: 50px;
    background: rgba(139,92,246,0.15); color: var(--accent-purple);
    font-size: 0.9rem; font-weight: 600; margin-bottom: 24px;
    border: 1px solid rgba(139,92,246,0.3);
}
.hero-title {
    font-family: var(--font-display); font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800; line-height: 1.1; margin-bottom: 24px;
}
.gradient-text {
    background: var(--gradient-primary); -webkit-background-clip: text;
    -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-subtitle { font-size: 1.2rem; color: var(--text-secondary); max-width: 600px; margin: 0 auto 40px; }
.hero-cta { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin-bottom: 60px; }

/* ===== Buttons ===== */
.btn {
    padding: 14px 32px; border-radius: 12px; font-weight: 600; font-size: 1rem;
    transition: var(--transition); display: inline-flex; align-items: center; gap: 8px;
}
.btn-primary {
    background: var(--gradient-primary); color: white;
    box-shadow: 0 4px 20px rgba(59,130,246,0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(59,130,246,0.4); }
.btn-secondary {
    background: rgba(255,255,255,0.06); color: var(--text-primary);
    border: 1px solid var(--border);
}
.btn-secondary:hover { background: rgba(255,255,255,0.1); transform: translateY(-2px); }

/* ===== Hero Stats ===== */
.hero-stats { display: flex; justify-content: center; gap: 48px; flex-wrap: wrap; }
.stat { text-align: center; }
.stat-num { display: block; font-family: var(--font-display); font-size: 2.5rem; font-weight: 800; background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.stat-label { font-size: 0.85rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }

/* ===== Sections ===== */
.section { padding: 100px 0; }
.container { max-width: 1280px; margin: 0 auto; padding: 0 24px; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-badge {
    display: inline-block; padding: 6px 16px; border-radius: 50px;
    background: rgba(59,130,246,0.1); color: var(--accent-blue);
    font-size: 0.85rem; font-weight: 600; margin-bottom: 16px;
}
.section-title { font-family: var(--font-display); font-size: 2.5rem; font-weight: 800; margin-bottom: 16px; }
.section-desc { color: var(--text-secondary); max-width: 600px; margin: 0 auto; font-size: 1.1rem; }

/* ===== Niveaux ===== */
.niveaux { background: var(--bg-secondary); }
.niveaux-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.niveau-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 40px 24px; text-align: center; transition: var(--transition);
    position: relative; overflow: hidden;
}
.niveau-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: var(--gradient-primary); opacity: 0; transition: var(--transition);
}
.niveau-card:hover { transform: translateY(-8px); border-color: rgba(59,130,246,0.3); box-shadow: var(--shadow); }
.niveau-card:hover::before { opacity: 1; }
.niveau-icon {
    width: 80px; height: 80px; border-radius: 20px; margin: 0 auto 20px;
    display: flex; align-items: center; justify-content: center;
    font-family: var(--font-display); font-size: 2rem; font-weight: 800;
    background: var(--gradient-primary); color: white;
}
.niveau-card h3 { font-family: var(--font-display); font-size: 1.3rem; margin-bottom: 8px; }
.niveau-card p { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 16px; }
.niveau-count { font-size: 0.8rem; color: var(--accent-blue); font-weight: 600; }

/* ===== Matières ===== */
.matieres-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.matiere-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 32px 24px; transition: var(--transition);
}
.matiere-card:hover { transform: translateY(-6px); box-shadow: var(--shadow); }
.matiere-icon { font-size: 2.5rem; margin-bottom: 16px; }
.matiere-card h3 { font-family: var(--font-display); font-size: 1.2rem; margin-bottom: 8px; }
.matiere-card p { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 16px; }
.matiere-tags { display: flex; gap: 8px; flex-wrap: wrap; }
.matiere-tags span {
    padding: 4px 12px; border-radius: 6px; font-size: 0.75rem; font-weight: 500;
    background: rgba(255,255,255,0.05); color: var(--text-muted);
}

/* ===== Outils ===== */
.outils { background: var(--bg-secondary); }
.outils-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.outil-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 32px 24px; text-align: center; cursor: pointer; transition: var(--transition);
}
.outil-card:hover { transform: translateY(-6px); border-color: rgba(139,92,246,0.3); box-shadow: var(--shadow); }
.outil-icon { font-size: 2.5rem; margin-bottom: 16px; }
.outil-card h3 { font-family: var(--font-display); font-size: 1.1rem; margin-bottom: 8px; }
.outil-card p { color: var(--text-secondary); font-size: 0.9rem; }

/* ===== Quiz ===== */
.quiz-intro {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 40px; text-align: center;
}
.quiz-selector {
    display: flex; align-items: center; gap: 16px; justify-content: center; flex-wrap: wrap;
}
.quiz-selector label { font-weight: 600; color: var(--text-secondary); }
.quiz-selector select {
    padding: 12px 20px; border-radius: 10px; border: 1px solid var(--border);
    background: var(--bg-primary); color: var(--text-primary); font-size: 1rem;
}
.quiz-container {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 40px; margin-top: 32px;
}
.quiz-progress { display: flex; align-items: center; gap: 16px; margin-bottom: 32px; }
.quiz-progress-bar {
    flex: 1; height: 8px; background: var(--bg-primary); border-radius: 4px; overflow: hidden;
    background: rgba(255,255,255,0.05);
}
.quiz-progress-bar::before {
    content: ''; display: block; height: 100%; border-radius: 4px;
    background: var(--gradient-primary); transition: width 0.5s ease;
}
.quiz-progress-text { font-weight: 600; color: var(--text-secondary); white-space: nowrap; }
.quiz-question { font-size: 1.3rem; font-weight: 600; margin-bottom: 24px; line-height: 1.5; }
.quiz-options { display: grid; gap: 12px; }
.quiz-option {
    padding: 16px 24px; border: 1px solid var(--border); border-radius: var(--radius-sm);
    background: var(--bg-primary); cursor: pointer; transition: var(--transition);
    font-size: 1rem; text-align: left;
}
.quiz-option:hover { border-color: var(--accent-blue); background: rgba(59,130,246,0.08); }
.quiz-option.correct { border-color: var(--accent-green); background: rgba(16,185,129,0.15); color: var(--accent-green); }
.quiz-option.wrong { border-color: var(--accent-red); background: rgba(239,68,68,0.15); color: var(--accent-red); }
.quiz-option.disabled { pointer-events: none; opacity: 0.6; }
.quiz-feedback {
    margin-top: 20px; padding: 16px; border-radius: var(--radius-sm); font-weight: 500; display: none;
}
.quiz-feedback.show { display: block; }
.quiz-feedback.correct-fb { background: rgba(16,185,129,0.1); color: var(--accent-green); border: 1px solid rgba(16,185,129,0.3); }
.quiz-feedback.wrong-fb { background: rgba(239,68,68,0.1); color: var(--accent-red); border: 1px solid rgba(239,68,68,0.3); }
.quiz-nav { margin-top: 24px; text-align: right; }
.quiz-result { text-align: center; padding: 40px; }
.quiz-score { font-family: var(--font-display); font-size: 4rem; font-weight: 800; background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.quiz-message { font-size: 1.2rem; color: var(--text-secondary); margin: 16px 0 32px; }

/* ===== Méthode ===== */
.methode-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.methode-card {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    padding: 32px 24px; text-align: center;
}
.methode-step {
    width: 48px; height: 48px; border-radius: 14px; margin: 0 auto 20px;
    display: flex; align-items: center; justify-content: center;
    font-family: var(--font-display); font-size: 1.2rem; font-weight: 800;
    background: var(--gradient-primary); color: white;
}
.methode-card h3 { font-family: var(--font-display); margin-bottom: 8px; }
.methode-card p { color: var(--text-secondary); font-size: 0.9rem; }

/* ===== Modal ===== */
.modal {
    position: fixed; inset: 0; z-index: 2000;
    display: none; align-items: center; justify-content: center;
    background: rgba(0,0,0,0.7); backdrop-filter: blur(8px);
}
.modal.show { display: flex; }
.modal-content {
    background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius);
    max-width: 600px; width: 90%; max-height: 85vh; overflow-y: auto; position: relative;
}
.modal-close {
    position: absolute; top: 16px; right: 16px; width: 40px; height: 40px;
    border-radius: 10px; background: var(--bg-primary); color: var(--text-primary);
    font-size: 1.5rem; display: flex; align-items: center; justify-content: center;
    transition: var(--transition); z-index: 1;
}
.modal-close:hover { background: rgba(239,68,68,0.2); color: var(--accent-red); }
.modal-body { padding: 40px; }
.modal-body h2 { font-family: var(--font-display); margin-bottom: 24px; }

/* Calculator */
.calc-display {
    background: var(--bg-primary); border: 1px solid var(--border); border-radius: var(--radius-sm);
    padding: 20px; text-align: right; font-size: 2rem; font-family: var(--font-display);
    margin-bottom: 16px; min-height: 70px; overflow: hidden;
}
.calc-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 8px; }
.calc-btn {
    padding: 16px; border-radius: 10px; font-size: 1.2rem; font-weight: 600;
    background: var(--bg-primary); color: var(--text-primary); border: 1px solid var(--border);
    transition: var(--transition);
}
.calc-btn:hover { background: rgba(255,255,255,0.08); }
.calc-btn.operator { background: rgba(59,130,246,0.15); color: var(--accent-blue); }
.calc-btn.equals { background: var(--gradient-primary); color: white; }
.calc-btn.clear { background: rgba(239,68,68,0.15); color: var(--accent-red); }

/* Tables */
.table-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-top: 16px; }
.table-card {
    background: var(--bg-primary); border: 1px solid var(--border); border-radius: var(--radius-sm);
    padding: 16px; text-align: center;
}
.table-card h4 { color: var(--accent-blue); margin-bottom: 12px; font-family: var(--font-display); }
.table-card p { font-size: 0.95rem; line-height: 2; }

/* Formules */
.formule-list { display: grid; gap: 16px; }
.formule-item {
    background: var(--bg-primary); border: 1px solid var(--border); border-radius: var(--radius-sm);
    padding: 16px 20px;
}
.formule-item h4 { color: var(--accent-purple); margin-bottom: 4px; }
.formule-item .formule { font-family: 'Courier New', monospace; font-size: 1.1rem; color: var(--accent-green); }

/* ===== Footer ===== */
.footer { background: var(--bg-secondary); border-top: 1px solid var(--border); padding: 60px 0 30px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo-text { font-size: 1.2rem; }
.footer-brand p { color: var(--text-muted); margin-top: 12px; font-size: 0.9rem; }
.footer-links h4 { font-family: var(--font-display); margin-bottom: 16px; font-size: 1rem; }
.footer-links a { display: block; color: var(--text-muted); font-size: 0.9rem; padding: 4px 0; transition: var(--transition); }
.footer-links a:hover { color: var(--text-primary); }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 24px; text-align: center; color: var(--text-muted); font-size: 0.85rem; }
.footer-bottom a { color: var(--accent-blue); }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .niveaux-grid, .matieres-grid, .methode-grid { grid-template-columns: repeat(2, 1fr); }
    .outils-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .nav-toggle { display: flex; }
    .nav-menu {
        display: none; position: absolute; top: 70px; left: 0; right: 0;
        background: rgba(10,14,26,0.98); padding: 24px; flex-direction: column;
        border-bottom: 1px solid var(--border);
    }
    .nav-menu.open { display: flex; }
    .hero-title { font-size: 2rem; }
    .hero-stats { gap: 24px; }
    .stat-num { font-size: 1.8rem; }
    .section-title { font-size: 1.8rem; }
    .niveaux-grid, .matieres-grid, .methode-grid, .outils-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .quiz-selector { flex-direction: column; }
    .hero-cta { flex-direction: column; align-items: center; }
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}
.animate-in { animation: fadeInUp 0.6s ease forwards; opacity: 0; }